How do I mix MP3 audio tracks?

Introduction.

Mixing of different audio tracks is not unusual. In fact, it is pretty usual.
All modern music is done separately for each instrument and voice, and only
later they are mixed into a single piece. Audio books are read with some musical
background that helps to deepen emotional experience. Sometimes it is just fun
to put unrelated things together to make people laugh, or to explore new
dimensions of ordinary things.

Well, isn't that a bit philosophic? We want to something real, don't we?

Let's consider a simple example of how to mix MP3 audio tracks with the help of Acoustica MP3 Audio
Mixer - an easy-to-use sound editor with professional capabilities.

Step 3: Add MP3 files to mix.

You can browse to your files and select the one you need. Preview is
available: the MP3 mixer starts to play selected file.

Step 4: Arrange tracks, add more tracks.

In order to mix MP3, you need at least two tracks. Of course, the program allows you to
record different sounds, for example, from microphone, so you can create another
track in this way. I have prepared my tracks (voice and music) earlier and just
want to mix them. But you may want to mix three or even more MP3 files together.
Just repeat step 3.

Acoustica MP3 Audio Mixer allows you to arrange tracks visually, by dragging
them to their positions. Interface is pretty obvious. If you drag a track to the
left, it will start earlier, to the right - the track will be played with delay.
There is a scale above the tracks showing time in seconds (you can zoom in or
out). Volume adjustments are very easy: click on a track and drag horizontal
line up or down.

To preview the results of your audio mixing, just click usual "Play" button on the
program's toolbar.

If you are satisfied with the results, click "Save".

Step 5: Save your mix as MP3 file.

The program offers you to save your work as project ("SoundGroup File") by
default. However, we need a ready-made product, so let's save our mix as MP3
file.

Done? Not yet.

The following window appears:

Here you can set codec, quality, and provide some meta-information (ID3 tag)
about the file, as title, author, year etc. By default quality is set to 192
kbit/s, which is good enough for most records.

Click "Save" to start saving the mix.

It will take some time, depending on your system, as the program should
encode audio. Wait until it finishes, then find output file in the folder
specified in step 5.